True, but I think that in reality, for someone other than God to make that call, is difficult as best.
I mean, how does one JUDGE anothers Christianity?
I mean outside the extreme examples of course.
This has been debated for sometime, when does one become Christian? when does "atonement" take hold? and once it does, how does an outside know? shoudl they know?
Paul and James seemd to have argued about the "fruits" of faith ( though not to the extent that some make it out to be), Augustine argued about it with the Donatists in that to expect complete "sameness" from all believers is not only unrealistic, it isn't biblical.